This application pertains to termite control.
Previous systems of electric termite control, as described in U.S. Pat. Nos. 4,223,468 and 4,366,644, used vibrators and oscillators for high voltage, high-frequency generation. These devices have limited power output, are prone to breakdowns, and require periodic maintenance.
Termite control has long been a vital commercial business. The annual economic loss from termites is estimated to be close to one billion dollars in this country, including not only damage but cost of treatment.
Moreover, the nature of the business, and the customers' demands and expectations, are such that a 100% success of results is required, even though the treatment is underground and not readily inspectable during the treatment procedure; and if there is any evidence of anything less from a 100% killing of termites, contractors with integrity and business-consciousness have to pay for costly re-treatments, warranty-fulfillments, etc.
Those disadvantages cannot be avoided readily, because the dispensing of an abundant extra, in order to assure a 100% kill, can run afoul of the ever-tightening governmental requirements against pollution and contamination.
The changes in termiticides through the years have caused changes in the amounts of application, and the hazards of soil-contamination of the soil away from the building site. And with increasing awareness of the vital need of better ecological considerations, a factor of increasing vitalness and of increasing awareness now for many years, optimum effectiveness of termiticide procedures has been an increasing yet unsatisfied need of the entire termite control industry.
Subterranean termites enter a wooden structure through holes and cracks in foundations and walls. The art is replete with techniques to prevent their entry.
The better known techniques are not usually long-lived. Foundations, for example, can and do crack, enabling the termites to enter the structure. Heaving of the ground or growth of roots often create voids through which the termites pass. There remains a need for an inexpensive, easily installed barrier which can withstand disruptive forces, discourage the entry of roots through it, and prevent the passage of termites.
The extermination industry has long relied on insecticides applied as sprays or streams. These are very cost effective, and over the years have not caused much objection. However, as awareness has grown about the potentially harmful effects of insecticides, resistance has arisen to their continued use, especially by chemically-sensitive persons.
In view of this increased awareness, it is surprising that with the advantages offered by the process described in the article, there has been no commercial use made of this technique, at least to the knowledge of the present applicants. Upon reflection, the applicants have concluded that it has suffered from lack of simple method of application, and also from means to keep the barrier in place and the conformity with adjacent structures once it is applied.
It is an object of this invention to provide a conveniently installed barrier to passage of termites, and methods and constructions which assure its long-lived effectiveness.
The invention relates to a method and apparatus for preventing termites and other crawling insects from entering, for example, houses or other structures inhabited or occupied by people and/or animals, and more particularly, relates to a method and apparatus for preventing termites from entering residential structures, commercial structures and industrial structures which structures are mounted on support and associated structures connected to ground.
At the present time, most residential structures, commercial structures, and industrial structures, which are mounted on support and associated structures, utilize highly toxic poisons and other devices placed across the insect pathway to prevent termites and other crawling insects and pests from reaching the residential, commercial, and industrial structures. This is particularly the case where termite or insect intrusion could cause structural damage and/or physical or emotional problems to people and/or animals inhabiting or working in the structure. With most of the current methods, the user or a contracted service must periodically replace the toxic substances in order to preclude termites and/or other crawling insects. The most effective toxic substance, chlordane, has recently been banned by the Environmental Protection Agency.
Therefore, it is an object of the present invention to provide a mechanical assembly mounted above ground on support and/or associated structures. This assembly has physical and other barriers arranged in a particular manner for preventing termites from reaching critical areas of residential structures, commercial structures, and industrial structures.
It is a further object of the present invention to provide unobtrusive devices that are relatively inexpensive, easy to install, quick to maintain, and environmentally safe, while having physical and other barriers for preventing termites from reaching critical area of residential structures, commercial structures, and industrial structures.
It is a further object of the invention to utilize a bonding agent to provide an imperious bond between the assembly and the support and associated structures. The purpose of the bonding agent is to seal off any spaces, between the assembly and the support and associated structures, which would have permitted the termites to bypass the invention and thereby gain access to the residential structures, commercial structures, and industrial structures.
It is also an object of the invention to provide an assembly which may be utilized on new construction, as a retrofit on existing structures, or as an integral portion of manufactured or modular structures at the time the structures are originally manufactured.
The invention concerns controlling of termites in building construction. Termites, insects of the order isoptera, have about 2,000 species, about 200 of which are known to be pests and cause damage to crops, buildings and furniture. Termite distribution is primarily tropical. They are also prevalent in the subtropics and temperate zones. In North American they reach as far north as Main and Vancouver.
The present invention is directed to subterranean dwelling species, which are dependent on moisture in the soil and which reach and destroy buildings and furnishings through foundations, either by wood in contact with soil, or by cracks in slabs and foundations. Termite nymphs divide into worker, soldier and alates or reproductors. New colonies are established by winged adults who are weak flyers, often blown in the wind for a few yards or hundreds of feet. The alight, shed their wings, pair and nest in soft wood or soil. The nests are sealed to preserve moisture. A first batch of eggs is laid, and in two to five years a colony matures. The queen may become as large as four inches long, laying more than 30,000 eggs a day during a lifetime, which may stretch over 20 or more years. The tendency of colonies to establish close to each other and the rapid development of established colonies cause the species to become extremely destructive. The termites are equipped with mouth parts for chewing wood, and their guts contain protozoans for dissolving wood. Once colonies are well established, it is difficult to destroy them.
Many systems have been devised for destroying wood dwelling termites. The most satisfactory may be expensive and difficult fumigations. Subterranean termites are mostly attacked by poisoning the ground before construction and filling a trench around a construction with chemicals, usually chlorinated hydrocarbons. Some below-ground pipe systems have been proposed, which install rigid pipes beneath the surface of the ground, especially beneath vertical walls. Insecticides are periodically released from the pipes.
Many present inventions remain with termite control. Foremost of the problems is the need to control termites with a minimal level of chemicals so that the chemicals do not migrate to ground water and cause long-term pollution. Another problem that exists is the distribution of termite control chemicals in a suitable manner to ensure destruction of all termites without overloading a ground system with the chemicals. Problems exist in ensuring against penetrations of slabs and foundations by unobserved cracks.
The predominant current usage of the permanent termite protection system of the present invention is as a fixture which is installed in wooden structures at the time of their construction.
The problem of damage caused to wooden structures by termites is not a new one.
Currently, a pest control technician usually uses a hand carrier sprayer to deposit the chemicals around the perimeter of the structure and onto those areas underneath the structure that can be reached by means of crawl spaces and the like. However, all too frequently, large areas under the structure cannot be reached by this means at all. More importantly, such areas are often some of most prone to termite infestation due to the fact that are particularly dark, damp, and secluded. Not only is this method ineffective because it does not reach some of the most needed locations, it is expensive. The time and effort required to accomplish this job is significant. Because of the expense involved, and because termite damage is one of those things that is far too easy to ignore until it too late, many home owners either neglect the task of termite control entirely or else they may attend to it all too infrequently.
An alternative method of termite control it to "tent" an entire structure and then to fumigate with the tent. Of course, the disadvantages in inconvenience to the residents of the extreme measure are obvious. Furthermore, this method is intended primarily to kill existing infestations, and is not very effective as a measure to provide long term protection. Certainly, it would be better to prevent the termite infestation which necessitates the need for this drastic sort of remedial action by regularly treating foundation areas of the structure with termite pesticides.
The principle of current enhancement by use of high voltage multi-frequency energy, calculated to deliver maximum electrical kill-energy at low power levels. Those termites near the point of energy application are killed instantly. Those more distant are eliminated by virtue of the effect of electrical energy on digestive processes and on feeding of the non-foraging elements of a social pest colony.
Energy can be applies at any point along the galleries and tubes or directly into the nest. Once the nest is located, an electrode is injected into it and the pests are eliminated by applying either the high-voltage radio frequency energy or the high-voltage multi-frequency electric energy directly to the electrode. Application of electricity to the nest has the effect of killing the queen termite, causing the colony to cease foraging and die out.
The proper magnitude of electric treatment power is monitored by the operator by use of accessories having visual indicators such as meters or incandescent lights. Also utilized with the probe gun and associated circuitry of the present invention is a dynamic conductance-test circuit, which by means of a calibrated or standard test specimen such as wood, permits the setting of proper power levels for the probe gun with regard to expected treatment conditions.
They are widely distributed in tropical countries, but also occur in the temperate parts of North and South America and a few have established themselves in Europe. Their food consists for the most part of wood, especially in a state of incipient decay, but they also eat a great variety of sub stances. The termite society consists for the most part of workers, wingless, sexually immature individuals. Besides these workers there is a less numerous caste of large-headed, blind strong-jawed soldiers. The workers collect food, form nests and tunnels, and care for the males, females, eggs, and larvae. The males and females have wings, which the latter lose after impregnation. Then, the female or queen undergoes a remarkable change, becoming enormously distended with eggs. The queen is extremely prolific, having been known to lay 60 eggs in a minute. In the spring the young winged males and females leave the nest in a swarm, after which pairing takes place; the survivors becoming the parents of new colonies.
Termites, the world over, are the most destructive of insect species attacking wood and cellulose products. Millions of dollars are lost annually in the United States as a direct result of termite damage by the subterranean termite. One of the most destructive subterranean species, Reticulitermes flavipes (Kollar), has established itself in the populous northeastern Unites States. Of the fifteen species of subterranean termites considered to be pests of major economic importance, four species of Reticulitermes, R. flavipes, R. hesperus, R. hageni, and R. virginicus, are responsible for most of the damage.